Multisegment oven scheme for Gouy phase shift compensation in second-harmonic generation

Area of Science:

• Nonlinear Optics
• Quantum Optics
• Materials Science

Background:

• The Gouy phase shift limits efficiency in nonlinear optical processes like second-harmonic generation (SHG).
• Tight focusing conditions exacerbate phase mismatch issues, particularly in long nonlinear crystals.
• Optimizing temperature profiles is critical for maintaining phase-matching conditions.

Purpose of the Study:

• To develop a theoretical model for a multisegment oven to counteract the Gouy phase shift.
• To achieve maximum efficiency in second-harmonic wave generation.
• To investigate the impact of multisegment ovens on SHG efficiency and crystal performance.

Main Methods:

• Theoretical modeling of a multisegment oven configuration.
• Numerical simulations based on an experimental setup with an MgO:sPPLT nonlinear crystal.
• Optimization of segment temperatures to re-establish phase-matching conditions.

Main Results:

• A three-segment oven demonstrated the potential for highest efficiency by canceling Gouy phase effects.
• Optimized multisegment ovens achieved SHG efficiencies exceeding 4.4% at a confocal parameter of 3.32.
• Multisegment ovens are essential for maximum efficiency in long crystals with large confocal parameters, showing up to a 2x increase in acceptance temperature bandwidth.

Conclusions:

• Multisegment ovens offer a viable solution to overcome Gouy phase shift limitations in SHG.
• Optimized temperature control in multisegment ovens significantly enhances SHG efficiency and power stability.
• This approach is critical for maximizing performance in advanced nonlinear optical systems, especially with extended crystal lengths.